Every year, in Britain alone, a staggering 1bn tampons and sanitary towels are used and disposed of – many ending up in the sewerage system.

If that figure gives you a PMT-type headache consider this: the average woman – if such a woman exists – uses 11,000 sanitary items during her lifetime, spending around £90 a year.

It may be tempting to suggest you look away now if you're at all squeamish about this subject, but that squeamishness, it seems, serves the large sanitary protection manufacturers very well and the environment very badly.

While we avoid talking about it, many of those towels, tampons and liners, with all their attendant plastic applicators and stayfresh perfumes, are being flushed unthinkingly down the toilet. Next time you do that, spare a thought for those whose job it is to manually scrape this sort of junk out of liquid sewage before it enters treatment plants, so that it can then be sent to landfill.

There are eco-friendly alternatives, however. The Mooncup is one of them. A silicone cup that collects menstrual blood, it's washable, reusable and about as green as you can get. Its growing popularity means it is no longer the preserve of hippy health shops. Boots now stock them in all their stores, you will find them on eBay and they're available to order from Amazon. According to Mooncup, medical research dating back as far as 1918 has found that the pesticides used in growing the cotton for tampons, and the bleach to make them white, can be absorbed into the body.

It's only when I come to try the Mooncup that I realise my relationship with Tampax tampons, which began when I was an unquestioning teenager 30 years ago, is my longest-held brand loyalty.

But the Mooncup, on paper at least, makes far more sense. It contains none of those bleaches or toxins and it won't cause toxic shock syndrome (TSS). There are 30 cases of this potentially fatal build-up of the bacterium Staphylococcus aureus in the UK each year and half are linked to tampon use. Two or three women die of TSS every year with teenage girls most at risk because they tend to change their tampons less frequently than they should.

Ever read the leaflet in your box of Tampax? I have now and even it suggests using a pad instead of a tampon at least once a day. "You can also essentially eliminate the risk of menstrual TSS by not using tampons," it adds ominously.

The Mooncup, which has been around for around 70 years in one form or another, has no history of TSS. It will, however, save you loads of money, last for years and take up hardly any room in your luggage. The £20 cups come in two sizes relating to age and whether you've had children or not. What, then, is not to like? I'm not squeamish and I think it's the name that's put me off as much as anything but I take the plunge and order one. A squidgy eggcup with a stem for removal, and the website address embossed handily around the edge, arrives. It looks like a piece of the plumbing system, which, I suppose, it is.

I have a couple of practices and while at first it seems alarmingly springy, within a very short time I'm whipping it in and out and feeling very proud of myself. You can also turn to YouTube for help.

Then it was time to use it for real. And you know what? It was fine. More than fine, actually. It was really interesting. "Oh, so it's only that much blood and that consistency," I found myself musing. I even felt I'd been cheated of this information about what my body produces, all these years.

It didn't leak or get stuck and I honestly couldn't feel it.

For the first time in aeons I didn't suffer a single stomach cramp. Mooncup's manufacturers put this down to the lower position of the cup in the vagina and the fact that it is non-absorbent and doesn't soak up natural secretions, as conventional tampons do.

The Mooncup's capacity is much greater than the most super-absorbent tampon so it can even cope on those days when you need 12 hours in bed. A couple of months down the line it has reduced the headstress I'd been suffering brought on by what I thought were heavy periods. In fact, I realise now, it was just the tampon's inability to cope, rather than my body's fault, and I haven't used a single back-up liner. Yes, there's a bit of faffing about with washing when you come to empty it every six or eight hours but you don't even need to do that. If you haven't any water to hand a quick wipe with loo roll is OK.

Removal, on the other hand, involves some fairly undignified suction noises. But that's a very small price to pay for something that significantly contributes to reducing your ecological footprint and makes the whole period palaver more tolerable.

I've also given the washable tampon-like Sea Pearls, made of sustainably harvested sea sponge, a whirl. They're slightly scratchy, and after the certainty of the Mooncup, I think I'll pass.

Of course, says my sister, a Mooncup convert of several years, when I relate all this back to her, but if you want to do the real hippy thing you should empty the blood from your Mooncup onto your compost heap. She hasn't gone that far. And neither will I. But, with equal certainty, I can say the Mooncup's here to stay.